Relationship between arterial stiffness and myocardial damage in patients with newly diagnosed essential hypertension

BackgroundArterial stiffness increases in hypertensive individuals. Arterial stiffness is associated with impairment of systolic and diastolic myocardial function in hypertension (HT). However, the relationship between arterial stiffness and serum heart-type fatty acid-binding protein (H-FABP) levels, a sensitive marker of myocardial damage, has not been previously examined in patients with HT. We investigate the relationship between serum H-FABP levels and arterial stiffness in patients with newly diagnosed HT.MethodsWe studied 46 (48.5 +/- 10.6, years) never-treated patients with HT and age-matched control group of 40 (47 +/- 8.6, years) normotensive individuals. H-FABP levels were determined in all subjects. We evaluated arterial stiffness and wave reflections of study population, using applanation tonometry (Sphygmocor). Carotid-femoral pulse wave velocity (PWV) was measured as indices of elastic-type, aortic stiffness. The heart rate-corrected augmentation index (AIx@75) was estimated as a marker of wave reflections.ResultsCarotid-femoral PWV (10.5 +/- 2.2 vs. 8.7 +/- 1.6, m/s, P = 0.0001) and AIx@75 (22.7 +/- 9.5 vs. 15 +/- 11, %, P = 0.001) were significantly higher in patients with HT than control group. H-FABP levels were increased in hypertensive patients compared with control group (21.1 +/- 14.8 vs. 12.9 +/- 8.5, ng/ml, P = 0.002). In multiple linear regression analysis, we found that the body mass index (beta = 0.42, P = 0.0001) and carotid-femoral PWV (beta = 0.23, P = 0.03) were significant determinants of H-FABP levels.ConclusionArterial stiffness is associated with serum H-FABP levels, a sensitive marker of myocardial damage, in patients with newly diagnosed HT.American Journal of Hypertension (2008). doi 10.1038/ajh.2008.235American Journal of Hypertension (2008); 21, 9, 989-993. doi 10.1038/ajh.2008.235.     

Measurement of pulse wave velocity: site matters

BACKGROUND: Aortic pulse wave velocity (PWV) predicts mortality from cardiovascular disease, ischaemic heart disease and stroke. However, a comparison of associations between PWV measured at different sites and atherosclerosis in coronary, carotid and femoral arteries has not been made. METHODS: In 159 men (ages 45-82 years) with and without known coronary artery disease, PWV measurements were made between carotid-femoral, carotid-radial and femoral-posterior tibial sites, using an ultrasound technique. Coronary artery calcification (CAC) scores were measured by multislice computed tomography. Carotid and femoral intima-media thickness (IMT) and presence of plaque were determined by ultrasound. Known coronary artery disease was confirmed by angiography. Participants were grouped into four categories of CAC score: 0-10, 11-100, 101-400, > 400 Hounsfield Units (HU). Measurements of blood pressure, heart rate and fasting bloods were made in all individuals. RESULTS: Carotid-femoral PWV correlated positively with CAC score and increased with incremental coronary calcification category (median carotid-femoral PWV 16.8 m/s in those with CAC score > 400 HU and 13.8 m/s in those with CAC score < 10 HU; P = 0.003). Carotid-femoral PWV also correlated with carotid and femoral IMT (P < 0.001, P = 0.004, respectively) and with carotid and femoral plaque (P = 0.001, P = 0.038, respectively). Increased carotid-femoral PWV also correlated with increasing age (P < 0.001), systolic blood pressure (P < 0.001), mean arterial pressure and pulse pressure (P < 0.001). Carotid-radial and femoral-posterior tibial PWV were not significantly associated with CAC score, carotid or femoral IMT or carotid plaque. CONCLUSIONS: Carotid-femoral PWV is a better indicator of atherosclerosis than either carotid-radial or femoral-posterior tibial PWV, and should be used preferentially in studies of atherosclerosis and in stratifying risk in clinical settings.     

高血压病患者动态血压与动脉顺应性的相关性研究

目的:探讨高血压病患者动脉顺应性的变化,及其与动态血压监测(ABPM)各指标间的相互关系。方法:对262例高血压病患者和104例正常人进行动态血压监测(ABPM)和脉搏波速度(PWV)测定。结果:高血压组的颈动脉-桡动脉(G-R)PWV、颈动脉-股动脉(C-F)PWV,24 h、白昼及夜间平均血压,平均脉压,心率,血压负荷均显著高于正常对照组(P<0.05~<0.01)。C-F PWV及C-R PWV与24 h、白昼及夜间平均血压,心率,血压负荷均呈显著正相关(r=0.108~0.406,P<0.05~<0.001)。C-F PWV比C-R PWV与平均收缩压和收缩压负荷的相关性更强。C-F PWV与动态脉压、年龄显著正相关(r=0.205~0.406,P<0.001)。结论:动脉顺应性减退是高血压的重要改变,大动脉顺应性与动态脉压、收缩压和年龄的关系更为密切。     

Comparability and reproducibility of the carotid-femoral pulse wave velocity measurements using a multi-element carotid tonometry sensor

To evaluate the comparability and reproducibility of the carotid-femoral pulse wave velocity (PWV) measured by the newly developed device compared to that measured by the standard device and the validity of brachial-ankle PWV as a substitute of carotid-femoral PWV. We measured aortic PWV twice in 21 normotensive males by using the standard devices and the newly developed device. We also measured brachial-ankle PWV in the same subjects. There was a strong, significant correlation between aortic (carotid-femoral) PWV measured by using two different devices (r = 0.741, P = 0.00012). Interquartile range of the differences of carotid-femoral PWV measured by Form (0.75 m/s (-0.36, 0.39)) was smaller than that by Complior (1.67 m/s (-1.03, 0.63)). There was no correlation between carotid-femoral PWV, measured by either device, and brachial ankle PWV. Our present results suggest that carotid-femoral PWV measured by using Form was comparable to, and may be more reproducible than, that measured by Complior that has been widely used as a predictable marker for cardiovascular events. Our results also suggest brachial-ankle PWV may not be a substitute for carotid-femoral PWV.     

Relationship between cardio-ankle vascular index (CAVI) and carotid atherosclerosis in patients with essential hypertension.

Aortic stiffness measured by aorta-iliac or carotid-femoral pulse wave velocity (PWV) predicts all-cause and cardiovascular mortality. Brachial-ankle PWV (baPWV) has been developed as a more convenient assessment of arterial stiffness. However, the problem with clinical use of baPWV is that the index itself is closely dependent on blood pressure. Recently, a new method, termed the cardio-ankle vascular index (CAVI), has been proposed in Japan to overcome the disadvantages associated with measuring PWV. However, its clinical usefulness has not yet been fully clarified. In the present study, we compared the usefulness of CAVI with that of ultrasound for evaluating atherosclerosis in patients with essential hypertension. CAVI was measured in 70 hypertensive patients. The intima-media thickness (IMT), cross-sectional distensibility coefficient (CSDC), stiffness parameter beta, and mean diastolic (V(d)) and systolic (V(s)) flow velocities were evaluated by carotid ultrasound. The V(d)/V(s) ratio, an index of peripheral arterial resistance, was also calculated. CAVI was positively correlated with IMT (r=0.360, p=0.0022) and stiffness beta (r=0.270, p=0.0239) and negatively correlated with V(d)/V(s) (r=-0.471, p<0.0001) and CSDC (r=-0.315, p=0.0079). Stepwise regression analysis revealed that age (r=0.475, p<0.0001) and pulse pressure (r=0.492, r<0.0001) were independent determinants of CAVI. These results suggest that CAVI is a useful clinical marker for evaluating atherosclerosis and arteriolosclerosis in patients with essential hypertension.     

Comparison of arterial functional evaluations as a predictor of cardiovascular events in hypertensive patients: the Non-Invasive Atherosclerotic Evaluation in Hypertension (NOAH) study

Increased arterial stiffness and impaired vasodilator response have been associated with cardiovascular events in high-risk patients. However, whether arterial changes predict the occurrence of hypertensive complications is still unclear. Therefore, we designed a hospital-based cohort study to examine the prognostic impact of arterial functional changes on stroke and cardiovascular diseases in hypertensive patients. The study employed 676 patients with essential hypertension. At baseline, we evaluated second-derived photoplethysmography, carotid-femoral pulse wave velocity (PWV), and forearm reactive hyperemia. We classified subjects into quartile groups according to the baseline measurements of these evaluations and assessed the ability of each measure to predict stroke and cardiovascular diseases (CVD). During a mean follow-up period of 57 months, 52 strokes, 40 CVD, and 22 deaths were recorded. Kaplan-Meier analysis revealed that patients in the highest quartile of PWV showed a higher frequency of stroke and CVD (p<0.0001) and total mortality (p=0.0016), and those in the highest quartile of reactive hyperemia showed a lower frequency of stroke and CVD (p=0.0415). A Cox hazard model identified that classification in the highest quartile of PWV (relative risk=2.717) and reactive hyperemia (0.416) were predictive of stroke and CVD after adjustment for other risk factors. In subjects who did not experience stroke or CVD before the study period (n=558), only PWV was related with the occurrence of stroke and CVD based on the Cox hazard model. In conclusion, increased aortic stiffness evaluated by PWV is more prognostic of cardiovascular events in hypertensive patients than several non-invasive atherosclerotic evaluations.     

Usefulness of brachial-ankle pulse wave velocity measurement: correlation with abdominal aortic calcification.

At present, brachial-ankle pulse wave velocity (baPWV) can be measured easily and noninvasively. We studied the correlation between aortic damage estimated by baPWV and that determined by measuring the length of abdominal aortic calcification (AAC) on X-ray films, which parameter has been significantly associated with cardiovascular morbidity and mortality. baPWV was measured using the form PWV/ankle brachial index (ABI) device in 97 patients free of end-stage renal failure or peripheral arterial disease. baPWV correlated significantly with age (r2=0.625, p<0.0001), was significantly higher in hypertensives than in normotensives (2,109+/-67 vs. 1,623+/-93 cm/s, p<0.0001), and correlated significantly with systolic blood pressure (r2=0.64, p<0.0001) and diastolic blood pressure (r2=0.397, p<0.0001). baPWV was significantly higher in diabetic patients than in nondiabetics (2,068+/-73 vs. 1,813+/-97 cm/s, p<0.05), but was similar in normolipidemic and hyperlipidemic patients. baPWV did not correlate with body mass index, fasting plasma glucose, total cholesterol, high density lipoprotein (HDL)-cholesterol, low density lipoprotein (LDL)-cholesterol or triglyceride levels, but correlated significantly with AAC length (r2=0.599, p<0.0001). Multiple regression analysis indicated that age, systolic blood pressure and AAC length were independent determinants of baPWV. Our results indicate that baPWV is useful for estimating aortic damage and could be a potentially useful predictor of vascular morbidity and mortality.     

Morning rise, morning surge and daytime variability of blood pressure and cardiovascular target organ damage. A cross-sectional study in 743 subjects.

OBJECTIVE: To evaluate in a large population the relationship between cardiovascular target organ damage and values of the night-to-morning rise of systolic blood pressure (MR-BP), the morning surge of BP at the moment of rising (BP surge) and daytime BP variability (standard deviation [SD] of daytime BP). METHODS: This was a cross-sectional study, evaluating 743 subjects, aged 30-75 years, 416 female, with normal renal function and no previous cardiovascular events. The population included: I-174 patients with type 2 diabetes, II-317 hypertensive patients with ongoing treatment over at least the previous 6 months, III-127 hypertensive patients untreated in the last 6 months, IV-125 healthy normotensive subjects. All underwent 24-hour ambulatory BP monitoring to calculate MR-BP, BP surge and SD of daytime BP. Target organ evaluation included: pulse wave velocity (PWV) (an indicator of aortic stiffness) in 711 subjects, left ventricular mass index (LVMI) in 185 subjects and 24-hour albuminuria in 239 subjects. RESULTS: In the population as a whole, BP surge, MR-BP and SD of daytime BP correlated significantly with PWV (r = 0.434, p < 0.0001; r = 0.126, p < 0.001; 0.337, p < 0.001, respectively), with LVMI (r = 0.447, p < 0.0001; r = 0.307, p < 0.001; 0.162, p < 0.05, respectively) and to a lesser degree with albuminuria (r = 0.126, p < 0.05; r = 0.083, NS; 0.082, NS, respectively). In the upper quintile of distribution of BP surge, the percentage of cases with abnormal PWV (>12 m/s) (21%), cardiac hypertrophy (53 %) and microalbuminuria (47 %) was significantly greater (p < 0.03) than that observed in the lower quintile (1%, 14% and 27%, respectively). BP surge correlated more strongly with indices of target organ damage than did MR-BP or SD of daytime BP, independently of night-time BP and nocturnal BP fall. CONCLUSIONS: In this large population, MR-BP, BP surge and daytime BP variability are strongly correlated with target organ damage severity, and are probably related to organ deterioration. Of the three, morning surge of BP at the moment of rising is more strongly related to organ damage than MR-BP, perhaps because unlike MR-BP, BP surge is independent of night-time BP values.     

Higher plasma homocysteine concentration is associated with more advanced systemic arterial stiffness and greater blood pressure response to stress in hypertensive patients.

Hyperhomocysteinemia has been reported to be associated with both vascular structure alteration and increased cardiovascular risk. This study examined whether hyperhomocysteinemia causes increased systemic arterial stiffness, thereby enhancing blood pressure response to stress in hypertensive patients. In 50 treated hypertensive patients, we studied brachial-ankle pulse wave velocity (PWV), a new measure for arterial stiffness, blood pressure response to stress, and blood pressure recovery after stress. Autonomic nervous activities were examined by spectral analysis of blood pressure and RR interval variabilities. Total plasma homocysteine and neurohumoral parameters were determined from fasting blood. Brachial-ankle PWV correlated with age (r=0.64, p<0.001), plasma homocysteine concentration (r=0.35, p<0.05), and systolic blood pressure (SBP) (r=0.62, p<0.001). Higher plasma homocysteine concentration was independently associated with greater brachial-ankle PWV (beta=0.388, p=0.01). We classified the subjects into high homocysteine (7.3 nmol/ml or over) and low homocysteine (7.2 nmol/ml or below) groups. Baseline SBP, plasma renin activity, aldosterone, and norepinephrine concentrations were similar between the two groups. However, the SBP values during stress and the recovery periods were higher in the high homocysteine group than the low homocysteine group even after adjusting for sex and age. The behavior of sympathetic vasomotor activity did not differ between the two groups. These data suggest that higher plasma homocysteine concentration is associated with increased systemic arterial stiffness, which may enhance blood pressure reactivity to stress in hypertensive patients.     

White coat effect in treated and untreated patients with high office blood pressure. Relationship with pulse wave velocity and left ventricular mass index.

OBJECTIVE: To evaluate in hypertensive patients whether the white coat effect is associated with target-organ damage and whether it is modified by anti-hypertensive therapy. METHODS: In a cross-sectional study we evaluated blood pressure (BP) measured in the office and by 24-h ambulatory blood pressure monitoring (ABPM), carotid-femoral pulse wave velocity (PWV) as an index of aortic stiffness, and left ventricular mass index (LVMI) in 88 subjects (aged 49 +/- 2 years) with white-coat hypertension (WCH, office BP > 140/90, daytime BP < 130/84 mmHg), 31 under antihypertensive therapy, 57 untreated, and in 115 patients with office and ambulatory hypertension (HT, aged 51 +/- 2 years, office BP > 140/90, daytime BP > 135/85), 65 under antihypertensive therapy, 50 untreated. In a longitudinal study in 15 patients with HT and in 11 patients with WCH we evaluated the influence of antihypertensive therapy (> 6 months) on office and ambulatory BP and on PWV. RESULTS: The intensity of the white coat effect (office BP-daytime BP) was greater in WCH than in HT. Taking all subjects, the white coat effect did not correlate with PWV (r = 0.08, ns) or with LVMI (r = 0.01, ns), whereas daytime BP correlated significantly with PWV (r = 0.41, p < 0.01) and with LVMI (r = 0.32, p < 0.05). WCH subjects showed lower PWV and LVMI than HT subjects. Treated and untreated WCH, with similar office and daytime BP, showed similar values of PWV and LVMI. Treated and untreated HT showed similar office BP values but treated HT showed lower daytime BP and PWV values. In the longitudinal study, antihypertensive therapy significantly reduced daytime BP and PWV values in the 15 HTs, whereas in the 11 WCH it did not alter daytime BP or PWV values. CONCLUSIONS: 1. In both WCH and HT (treated and untreated) the intensity of the white coat effect does not reflect either the severity of hypertension measured by target organ damage or the efficacy of antihypertensive treatment. 2. In WCH antihypertensive therapy does not improve either ambulatory BP values or damage to target organs.     

Low total antioxidative capacity levels are associated with augmentation index but not pulse-wave velocity

It is well known the relationship between oxidative stress and vascular function. However, association between total antioxidative capacity and arterial stiffness was not studied in patients with hypertension (HT). This study investigated whether total antioxidative capacity is associated with arterial stiffness and wave reflections. We studied 46 (age 48.5 ± 10.6 years) never treated patients with HT and age-matched control group of 40 (age 47 ± 8.6 years) normotensive individuals. Total antioxidative capacity level was determined in all subjects. We evaluated arterial stiffness and wave reflections of the study population, using applanation tonometry (SphygmoCor). Carotid-femoral pulse-wave velocity (PWV) was measured as index of aortic stiffness. The heart rate-corrected augmentation index (AIx@75) was estimated as a composite marker of wave reflections and arterial stiffness. Carotid-femoral PWV (10.5 ± 2.2 vs 8.7 ± 1.6, m/s, P = 0.0001) and AIx@75 (22.7 ± 9.5 vs 15 ± 11, %, P = 0.001) were significantly higher in patients with HT compared with age-matched control subjects. Total antioxidative capacity level (274 ± 70 vs 321 ± 56 μmol/l, P = 0.001) was significantly lower in hypertensive patients than controls. In the whole population, total antioxidative capacity level negatively correlated with AIx@75 (r = −0.24, P = 0.02) in univariable analysis, but not with carotid-femoral PWV (r = −0.08, P = 0.43). Also, we found that total antioxidative capacity level (β = −0.21, P = 0.03) was an independent determinant of AIx@75 in multivariable analysis. Our results suggest that the decrease in the ability of antioxidant defenses contributes significantly to increased wave reflections.     

Brachial-ankle pulse wave velocity is an independent risk factor for microalbuminuria in patients with essential hypertension--a Japanese trial on the prognostic implication of pulse wave velocity (J-TOPP).

Brachial-ankle pulse wave velocity is a new measure of arterial stiffness. The clinical significance of brachial-ankle pulse wave velocity as a measure of early vascular damage remains unclear. We examined the hypothesis that higher brachial-ankle pulse wave velocity is associated with a much greater risk of albuminuria by employing a cohort of 718 never-treated hypertensive patients registered in a prospective study. The 718 patients consisted of 500 patients with normoalbuminuria (69.6%), 191 patients with microalbuminuria (26.6%) and 27 patients with macroalbuminuria (3.8%). The prevalence of microalbuminuria increased with a graded increase in brachial-ankle pulse wave velocity (17.6, 22.8, 28.2 and 39.6%, p < 0.0001). The prevalence of macroalbuminuria remained constant until the third grade group of the brachial-ankle pulse wave velocity but increased significantly in the highest grade group compared with the lower grade groups (2.3, 3.2, 2.3, 9.9%, p < 0.0001). Age, systolic and diastolic blood pressure, pulse pressure, heart rate, and fasting glucose concentration were also significantly increased with an increase in brachial-ankle pulse wave velocity (p < 0.0001 for all). Multiple logistic regression analysis has shown that systolic blood-pressure, fasting blood glucose, and brachial-ankle pulse wave velocity are significant risk factors for microalbuminuria. After adjusting for other risk factors, the odds ratio for an increase of 200 cm/s in brachial-ankle pulse wave velocity was 1.192 (95% confidence interval: 1.022-1.365; p < 0.05). These data suggest that brachial-ankle pulse wave velocity is an independent risk factor for microalbuminuria and could be used as a marker for early vascular damage in never-treated hypertensive patients.     

A1166C polymorphism of angiotensin II type 1 receptor, blood pressure and arterial stiffness in hypertension

OBJECTIVE: To study the association of the AC polymorphism of angiotensin II type 1 receptor gene (AGTR1) with blood pressure and central arterial stiffness in a population of hypertensive patients referred to hospital for further work-up. METHODS: One hundred and eighty-five patients, referred to our department from April 1998 to February 2002, were included. Blood pressure was measured by conventional and 24-h ambulatory methods, and arterial stiffness by carotid-femoral pulse wave velocity (PWV) determination. Genotyping for the AGTR1 AC polymorphism was performed by polymerase chain reaction. RESULTS: AGTR1 AC polymorphism was not associated with systolic or diastolic blood pressure, measured either by conventional (P=0.89 and P=0.67, respectively) or by 24-h ambulatory (P=0.57 and P=0.56, respectively) methods. Conversely, this polymorphism was significantly associated with PWV (P=0.006) and had a dose-allele effect, PWV increasing with the number of A alleles (10.6 +/- 2.4 m/s in CC, 11.9 +/- 2.5 m/s in AC and 12.7 +/- 2.7 m/s in AA patients, P=0.002). Multiple regression analysis showed that AC polymorphism was still independently associated with PWV (P=0.01) and was the third most important determinant of PWV after age (P <0.0001) and 24-h mean blood pressure (P <0.0001). CONCLUSION: In our study population, central arterial stiffness assessed by PWV was significantly and independently associated with the AC polymorphism, increased PWV being associated with the presence of the A allele. Further investigations are required for identification of the underlying mechanisms.     

Matrix metalloproteinase-9 polymorphism contributes to blood pressure and arterial stiffness in essential hypertension

Arterial stiffness is an independent predictor of cardiovascular events in a hypertensive population. Serum levels of matrix metalloproteinase (MMP)-9 are associated with arterial stiffness and predict cardiovascular risk. We investigated the role of MMP-9 polymorphism -1562C>T on blood pressure (BP) and arterial stiffness in a newly diagnosed hypertensive population. Untreated hypertensive patients (n=215, mean age 46+/-13 years) were studied. Supine BP, carotid-femoral pulse wave velocity (PWV) and augmentation index were assessed. Serum biochemistry and plasma MMP-9 concentrations were measured and genotyping performed following extraction of genomic DNA. BP, aortic PWV and serum MMP-9 levels were significantly higher in T-allele carriers of the -1562C>T polymorphism with a significant gene-dose effect (P<0.0001). In a stepwise regression model adjusting for known or likely determinants, the 1562C>T polymorphism emerged as an independent predictor of systolic BP (R(2)=0.25, P<0.0001), diastolic BP (R(2)=0.16, P<0.0001) and PWV (R(2)=0.47,P<0.0001). This is the first study to show the effect of MMP-9 polymorphism on BP and aortic stiffness in a hypertensive population. These results suggest that hypertensive patients carrying the T allele may be at increased risk of cardiovascular events.     

Acute effects of oral melatonin administration on arterial distensibility, as determined by carotid-femoral pulse wave velocity, in healthy young men

The aim of the present study was to investigate the effects of melatonin administration on arterial distensibility by using carotid-femoral (aortic) pulse wave velocity (PWV) measurements in healthy young men. Ten men were studied (five men in the melatonin group and five men in the placebo group) by physicians. Carotid-femoral (aortic) PWV, blood pressure and plasma melatonin were measured in the supine position before and 60 min after oral administration of melatonin or placebo. Although carotid-femoral (aortic) PWV, systolic blood pressure and mean blood pressure were decreased, pulse wave propagation time and plasma melatonin levels were increased at 60 min after oral melatonin (1 mg) administration (P=0.04, P=0.04, P=0.04, P=0.04 and P=0.04, respectively). No significant differences were found between all parameters in the placebo group (P>0.05). In conclusion, these findings indicate that melatonin administration, compared with placebo, decreased carotid-femoral PWV and systolic blood pressure in the supine position in healthy young men. Administration of melatonin may have an inhibitory effect on sympathetic tone.     

Augmentation index and central aortic stiffness in middle-aged to elderly individuals

BACKGROUND: Increased aortic stiffness contributes to systolic hypertension and increased cardiovascular risk. The augmentation index (AI), ie, the percentage of central pulse pressure attributed to reflected wave overlap in systole, was proposed as a noninvasive indicator of increased arterial stiffness. We evaluated this hypothesis by investigating relations between AI and other direct measures of aortic stiffness. METHODS: Tonometric carotid- and femoral-pressure waveforms, Doppler aortic flow, and aortic-root diameter were assessed in 123 individuals with uncomplicated systolic hypertension and 29 controls of comparable age and sex. Carotid-femoral pulse-wave velocity (PWV) was assessed from the carotid-femoral time delay and body-surface measurements. Aortic PWV was assessed from the ratio of the upstroke of carotid pressure and aortic flow velocity and was used to calculate proximal aortic compliance as [aortic area]/[1.06 x (aortic PWV)(2)]. RESULTS: Partial correlations (adjusted for age, sex, presence of hypertension, height, weight, and systolic ejection period) showed no association between AI and carotid-femoral PWV (R = -0.05, P = .54). The AI was significantly though weakly related directly with aortic compliance (R = 0.21, P = .012) and inversely with aortic PWV (R = -0.198, P = .017). However, higher stiffness (lower compliance and higher PWV) was associated with lower AI. CONCLUSIONS: Increased AI is not a reliable surrogate for increased aortic stiffness. Decreasing AI with decreasing compliance (increasing aortic stiffness) may be attributable to impedance matching and reduced wave reflection at the interface between the aorta and the muscular arteries.     

Effect of long-acting isosorbide-5-mononitrate administration on large artery distensibility in patients with essential hypertension.

To evaluate the clinical efficacy of long-acting nitrates, isosorbide-5-mononitrate (IS-5-MN), on large artery distensibility in patients with essential hypertension. Large arterial distensibility was assessed by automatic noninvasive measurement of the carotid-femoral pulse wave velocity (PWV). Seventeen patients aged 62.53+/-7.94 years (mean+/-SD) with essential hypertension undering long-term antihypertensive therapy were studied in this trial. PWV was measured 2 weeks and 4 weeks after oral administration of IS-5-MN (30 mg once daily) with previous therapy. There was no significant difference in systolic blood pressure, diastolic blood pressure, pulse pressure or heart rate at 2 weeks and 4 weeks after treatment compared with baseline. The carotid-femoral PWV decreased significantly at 2 and 4 weeks after treatment (p<0.05, p< 0.05, respectively). Long-acting nitrates have potential value in improving large arterial distensibility in patients with essential hypertension independent of blood pressure alteration. It might be used as an effectively additive drug in hypertension control.     

Associations between arterial stiffness and platelet activation in normotensive overweight and obese young adults

Obese individuals have elevated platelet activation and arterial stiffness, but the strength and temporality of the relationship between these factors remain unclear. We aimed to determine the effect of increased arterial stiffness on circulating platelet activity in overweight/obese young adults. This analysis included 92 participants (mean age 40 years, 60 women) in the Slow Adverse Vascular Effects of excess weight (SAVE) trial, a clinical trial examining the effects of a lifestyle intervention with or without sodium restriction on vascular health in normotensive overweight/obese young adults. Carotid-femoral (cf), brachial-ankle (ba) and femoral-ankle (fa) pulse wave velocity (PWV) served as measures of arterial stiffness and were measured at baseline and 6, 12 and 24 months follow-up. Platelet activity was measured as plasma β-thromboglobulin (β-TG) at 24 months. Higher plasma β-TG was correlated with greater exposure to elevated cfPWV (p?=?0.02) and baPWV (p?=?0.04) during the preceding two years. After adjustment for serum leptin, greater exposure to elevated baPWV remained significant (p?=?0.03) and exposure to elevated cfPWV marginally significant (p?=?0.054) in predicting greater plasma β-TG. Greater arterial stiffness, particularly central arterial stiffness, predicts greater platelet activation in overweight/obese individuals. This relationship might partly explain the association between increased arterial stiffness and incident atherothrombotic events.     

Brachial-ankle pulse wave velocity: an index of central arterial stiffness?

Brachial-ankle pulse wave velocity (baPWV) is a promising technique to assess arterial stiffness conveniently. However, it is not known whether baPWV is associated with well-established indices of central arterial stiffness. We determined the relation of baPWV with aortic (carotid-femoral) PWV, leg (femoral-ankle) PWV, and carotid augmentation index (AI) by using both cross-sectional and interventional approaches. First, we studied 409 healthy adults aged 18-76 years. baPWV correlated significantly with aortic PWV (r = 0.76), leg PWV (r = 0.76), and carotid AI (r = 0.52). A stepwise regression analysis revealed that aortic PWV was the primary independent correlate of baPWV, explaining 58% of the total variance in baPWV. Additional 23% of the variance was explained by leg PWV. Second, 13 sedentary healthy men were studied before and after a 16-week moderate aerobic exercise intervention (brisk walking to jogging; 30-45 min/day; 4-5 days/week). Reductions in aortic PWV observed with the exercise intervention were significantly and positively associated with the corresponding changes in baPWV (r = 0.74). A stepwise regression analysis revealed that changes in aortic PWV were the only independent correlate of changes in baPWV (beta = 0.74), explaining 55% of the total variance. These results suggest that baPWV may provide qualitatively similar information to those derived from central arterial stiffness although some portions of baPWV may be determined by peripheral arterial stiffness.     

Endothelin gene variants and aortic and cardiac structure in never-treated hypertensives

Background: The polymorphism of several candidate genes has been studied in relation to essential hypertension and cardiovascular complications. Target organ damage in essential hypertension is a complex disorder influenced by multiple genetic and environmental factors. The possible contribution of endothelin gene variants to target organ damage in hypertension in humans has not been studied in depth.Procedure: We assessed the influence of genetic variants of components of the endothelin system ETAR -231A/G, 1363C/T, ETBR 30G/A and endothelin-1 (ET-1) 138insertion/deletion (I/D) on aortic stiffness, left ventricular geometric, and radial artery parameters in 528 never-treated hypertensive subjects of European origin. The study population included 314 men and 214 women with a mean age of 48 ± 0.5 years (±SEM). In samples of patients, aortic stiffness was assessed with carotid-femoral pulse wave velocity (PWV). Radial artery thickness was measured with an echotracking angiometer and left ven-tricular geometric parameter with standard echographic procedures.Results: The main results showed that the ETAR-231A/G (P = .022) and the ETBR 30G/A (P = .026) receptor gene variants influenced PWV level in women. The −231G and 30G alleles were associated with a codominant increase in PWV, explaining 18.6% of its variability (P = .005). In men, the ETBR 30G/A receptor gene variant was also related to the level of radial artery parameters (P = .02). No association between the 138I/D polymorphism of the ET-1 gene and left ventricular and radial artery parameters was observed in either men or women.Conclusions: These results indicate that the influence of endothelin system genes can be detected first on arterial parameters.